Lighting fixture back plate



FIG. 1 is a perspective view of lighting fixture back plate showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof, the bottom plan view being a mirror image; and,

FIG. 4 is a right side elevational view thereof, the rear view being a mirror image. 

The ornamental design for a lighting fixture back plate, as shown. 